Plug type valve



April 26, 1955 Filed Jan. 8, 1953 2 Sheets-Sheet 1 82 I 80 t sa- 3 94 86 44 C 64 a H u II /4 [0 II 76 J 2 70 ze EWEZEMOOQ,

April 26, 1955 E. E. MOODY PLUG TYPE VALVE 2 Sheets-Sheet 2 Filed Jan. 8, 1953 United States Patent This application is a continuation-in-part of the application of Elliott E. Moody for Improved Plug Type Valve, Serial No. 291,610, filed June 4, 1952, now abandoned.

This invention relates to valves and is situations because of However, they have one disadvantage, namely, the difiiculty of openmg and closing the valve due to the large frictional 1resistance between the valve and the valve seating surace.

rotated. This invention is concerned solely with the nonlubricated type of plug valve.

to open a nonlubricated plug valve of the type known to the prior art,

is is time consuming and in sidered objectionable. Various tofore provided for lifting the sition so as to mak means have been herevalve from seated poto turn the valve easily vice versa.

the valve merely far as it will go the valve occurring automatically. To close the valve the operator merely reverses the procedure.

Accordingly, one of the objects of the present invention is the provision of automatically operating while valve with a corresponding valve seat on the bonnet. Thus, repacking operations can be conducted at any valve setting.

The foregoing objects of the invention particularly understood by panying drawings in which:

Fig. I is a vertical section of the valve showing the construction for causing automatic opening of the valve, the valve being shown in closed position.

Fig. 2 is a vertical section of the valve shown in Fig. 1 broken away in part with the valve shown in open position.

Fig. 3 is a sectional plan view taken on the line 3-3 of Fig. 1.

Fig. 4 shows an alternative form of spring mechanism for causing automatic opening of the valve.

Referring now to 'the drawings, it will be observed that the valve comprises a casing 2 adapted to may be more reference to the accom- The method of connecthe pipes has no bearing on the The plug valve 8 is constructed to act integrally with an outer hollow stem 18 to which is fastened a handle or other suitable device 20 designed to provide auxiliary means if needed for imparting rotary motion to the stem 18 and the attached valve 8. The extent of the rotary motion of handle 20 is limited to and stops 22 and 23 (see Fig. 3) are provided at suitable positions so that the valve will be tion 26 at the lower interior of outer stem 18, the threads with corresponding threads seats 6 and an upper valve seat 30 located in the valve cap or bonnet 36. Seat 30 is concentric with the vertical axis of the valve and surrounds the lower end of outer stem 18. The plug valve 8 1s also provided with an upper seating surface 32 which is so shaped as to make intimate tight contact with the upper valve seat 30 when the valve is in uppermost position. The purpose of bringing upper seating surface 32 into engagement with the upper valve seat 30 is two-fold, namely, (1) to lock the plug valve in position against rotation when it is in other than fully closed position, and (2) to provide a tight seal against leakage from the area 16 outwardly about outer stem 18 to a stufling box 34. By providing the tight seal between valve seat 30 and the upper seating surface 32 when the valve is in uppermost position, the stuffing box may be repacked while fluid under pressure is maintained within the valve in area 16. v

The valve bonnet or cap 36 is securely attached to the top of the valve casing b of tap bolts 38. The

casing and cap together form a valve body. A tight fit at 40 exists between the casing and cap so that no fluid can escape. Other means of securing the cap to the easing could, of course, be used but such variation would in no way affect the invention herein disclosed.

Extending upwardly from cap 36 is a vertical tubular portion 42 which contains the stufling box and through which pass the Also extending upwardly from the cap 36 is a yoke 44 which is shown most clearly in Fig. 3. At the top of the yoke is a yoke collar 46 shown in section in Figs. 1 and 2. This collar has a recessed portion 48 which is dimensioned and proportioned to receive and act as a housing for a collar 50 which is affixed to inner stem 28. A companion flange 52 is securely attached to the yoke collar by means of tap bolts The companion flange is correspondingly recessed and proportioned to fit about the upper portion of the collar 50 with adequate clearances to permit rotary motion of the collar within the recess in the yoke collar.

A hand wheel 56 is secured to the upper end of the inner stem 28 thereby providing means for causing manual rotation of the inner stem. It will be understood, however, that a lever or other mechanical device might be substituted for the hand wheel for imparting rotation to the inner stem.

Attached to cap are a pair of ends and threaded at act to secure a gland follower stem 18 to press box 34. By removing the nuts 62 and 64, the gland follower can be raised to a height suflicient to permit packing or repacking of the stuffing box. With the packing prop erly in place and with the gland follower repositioned, the nuts 62 and 64 may then be replaced on studs 58 and 60 and tightened sufficiently to cause the gland to hold the packing under proper pressure in the stufflng box.

Fig. 1 shows the valve in fully closed position. In this position the passageway is at right angles to the port opening 12. The valve seating surface 14 is in intimate contact with the seats 6 and the flow of fluid through the valve is effectively stopped. In this fully closed position, the handle is as shown in full line in Fig. 3. Further clockwise movement of the handle is prevented by its engagement with stop 23 which is attached to yoke 44. The seating surface 14 of the plug valve is forced downwardly and maintained in tight engagement with seats 6 by the application of rotary clockwise movement to hand wheel 56. By turning the wheel to the right, the threads 24 and 26 act to force the valve downwardly since the inner stem 28 is held against vertical movement by the collar 50.

The construction which causes automatic turning and opening of the plug valve 8 as it is moved upwardly from seat 6 to engage the upper valve seat are shown in Figs. 1, 2 and 3. The hollow valve stem 18 has its upper end located within the confines of a helical spring 80, the upper end of which is secured as by welding at 82 to the under side of the yoke collar 46. Inner stem 28 also passes within the spring 80.

The upper end of the hollow valve stem 18 is threaded with a double thread 84 and 86, both threads being of steep pitch and of the square type. These threads at opposite positions are in engagement with lugs 88 and 90 that are affixed to the inside of the lower convolutions of the sides of the tubular portion 42 of the studs 58 and 60, pivoted at their lower their upper ends. Nuts 62 and 64 66 in position about outer downwardly against packing 68 in stuffing the spring. The handle 20 is also stem 18 by a key 91 in the manner heretofore explained, and acts in combination with the stops 22 and 23 as means for limiting the rotation of stem 18. As can be seen in Fig. 3, the handle 20 permits stem 18 to rotate through a maximum angle 0 90 When handle 20 is at the left against stop 23, the valve is in closed position. When it is at the right against stop 22, the valve is in open position.

The operation of the foregoing automatic construction is as follows: When the operator desires to open the valve, he will rotate the wheel 56 and stem 28 in a counterclockwise direction. This will cause valve 8 to be raised from its seats 6, and hollow stem 18 will move further upwardly into the lower end of spring 80. The co-action of the spring carried lugs 88 and 90 with the threads 86 as the stem 18 moves upwardly will cause the stem 18 and the valve 8 to be rotated in a counter-clockwise direction, which movement, of course, is assisted to some degree by the counterclockwise movement of the threads 24 of the inner stem 28 with respect to the threads 26 in the plug valve. As the raising of valve 8 proceeds, the rotation thereof will continue until it has been turned a full 90, the engagement of handle 20 with the stop 22 limiting further rotational movement. At this point, the valve will be fully opened, but the upper valve surface 32 will not as yet have come into engagement with the upper valve seat 30. Accordingly, the operator continues rotation of wheel 56 until the seats 30 and 32 are brought into contact. Further upward movement of valve stem 18 to complete the seating of surfaces 30 and 32 is permitted by virtue of the longitudinal compressibility of spring 80. In this way valve 8 can be turned from fully closed to fully open position during the period it is free of engagement with the lower seats 6 or the upper seat 30.

Conversely, when the valve is to be closed, wheel 56 is rotated clockwise, valve 8 is moved downwardly to be freed from seat 30 and then as downward movement continues, the co-action of lugs 88 and 90 with threads 84 and 86 will rotate valve 8 an arc of 90 clockwise to move it to closed position in will engage stop 23. ment will bring the valve into engagement with the seats 6 to complete the closing operation. Spring 80 may be stretched a trifle when closing is complete.

When the valve is in upper locked position, there will be appreciable clearance between the faces of seats 6 and the seating surface 14 of the plug valve. Since fluids often pass through the valve at high velocities and pressures, the lower end of the plug valve might be caused thereby to vibrate or deflect in an undesirable manner. In order to prevent such vibration or deflection, there is provided at the bottom of the plug valve an extension 70, preferably cylindrical in cross-section and axially aligned with the valve. This extension fits closely within the confines of a socket 72 in the bottom of the valve casing. As the valve is moved up and down, extension correspondingly moves in the socket. Since it is axially aligned with the valve, the extension in no way interferes with the opening or closing operation, but, on the contrary, assists in that it holds the lower end of the valve in correct axial alignment with respect to the valve seats. Should any fluid became trapped in the lower part of socket 72, provision is made for its escape upon the descent of the valve in the form of a small vertical passage 74 which leads into a transverse passage 76 that empties into the open area 16 that surrounds the plug valve.

A modified type of spring element is shown in Fig. 4. Here, instead of using a helical spring such as 80, there is shown a bellows 92, having its upper end fixed to the frame at 94 and with its lower end 96 surrounding the upper end of stem 18. The bellows 92 is in the general form of a doughnut and is compressible and extensible in a lengthwise direction, but has practically no torsional movement under the forces which are applied in the opening and closing of the valve. The thread 84 and 86 on stem 18 and the lugs 88 and 90 on the bellows are the same as those shown in F' If preferred a single thread and single lug only could be used as it is obvious that the number of threads and cooperating lugs is a matter of choice. believed apparent that the operation of a valve equipped with a bellows 92 will be the same as that of the valve equipped with spring as shown in Fig. 6.

it is my intention to cover attached to the valve all changes and modifications connected to spring element and in engagement With said thread to cause rotation of said stem and plug valve from closed to open position as said plug valve is being raised.

lve comprising a valve body,

than said main valve seats.

3. A valve comprising a valve body, mam valve seats therein to neglrglble torsional movement under the loads to be apnection with piping,

main valve seats.

valve body, mam valve seats conical plug valve, a

said plug said upper valve seat and bearing upper valve seat being located at the only place of egress from the interior of said valve body other than said main valve seats.

5. A valve comprising a valve body, valve therein and a pair of oppositely sponding seats, a stem extending from through an opening in said body, means for raising said plug valve from means for rotating said plug valve comprising a spring element having longitudinal a conical plug disposed corresaid plug valve 6. A valve comprising in combination, a casing for con- 21 sfem fixed to said said casing, packing for preventing leakage of said casing along said valve stem, plug valve from fluid from means for raising said means for rotating said 7. A valve comprising in combination, a casing for connection with piping, a conical plug valve in said casing, said plug valve and extending through said casing, packing for preventing leakage of fluid from said casing along said valve stem, means for raising said plug valve from seated position, said raising means comprising a threaded element vertically fixed with respect to said casing and in threaded engagement with an element fixed with respect to said plug valve, means for rotating said plug through a predetermined angle, said rotating means comprising a spring element having longitudinal compressibility but negligible torsional movement under the loads to be applied, said element having one end fixed with respect to said valve casing and the other end surrounding the upper portion of said valve stem, a thread on the exterior of said valve stem and a thread engaging element connected to said spring element and in engagement with said thread to cause rotation of said stern and plug valve from closed to open position as said plug valve is being raised, means for supporting the lower end of said plug valve when said plug valve is raised from seated position, and means for sealing said stem from the interior of said casing when said plug valve is in maximum raised position whereby said packing may be removed and replaced without is in operation.

8. A valve comprising in combination, a casing for connection with piping, a conical plug valve in said casing, a stern fixed to said plug valve and extending through said casing, packing for preventing leakage of fluid from said casing along said valve stem, means for raising said plug valve from seated position, means for rotating said plug valve through a predetermined angle, said rotating means comprising a spring element having longitudinal compressibility but negligible torsional movement under the loads to be applied, said element having one end fixed with respect to said valve casing and the other end surrounding the upper portion of said valve stem, a thread on the exterior of said valve stem and a thread engaging element connected to said spring element and in engagement with said thread to cause rotation of said stern and plug valve from closed to open position as said plug valve is being raised, means for supporting the lower end of said plug valve when said plug valve is raised from seated position, and means for sealing said stem from the interior of said casing when said plug valve is in maximum raised position whereby said packing may be removed and replaced without loss of fluid while said valve is in operation, said means for sealing said stern comprising a valve seat and a cooperating valve surface on the upper part of said valve.

References Cited in the file of this patent 

